Ministers were criticised yesterday after it emerged that the government has spent hundreds of thousands of pounds of taxpayers' money on documentaries.

The media regulator Ofcom confirmed it would examine claims that one of the programmes, Beat: Life on the Street, which focused on the role of police community support officers, broke programme sponsorship rules when it aired on ITV. Critics say the programme, which was commissioned by the Home Office and received £800,000 in government funding, portrayed the officers as helpful and effective, despite criticism of the scheme from opposition MPs and the police.

Media freedom campaigners and opposition politicians said last night it was inappropriate for the government to fund documentaries which purport to be independent and objective.

John Whittingdale, the Tory MP who chairs the Commons media committee, said any programmes that were funded and commissioned by the government must be clearly labelled.

"I think that it is very dangerous for the government to get involved in funding documentaries that deal with politically controversial topics such as this one on police community support officers," he said.

"It may be that there is sometimes a need for the government to make information films on other less controversial issues but it is crucial that these are clearly labelled as government-backed projects."

It is thought ministers have spent almost £2m on at least eight television series or programmes in the past five years. Subjects have ranged from an army expedition to climb Everest to a film encouraging people to donate blood and another on the dangers of importing food and animal products into the UK.

Ofcom rules state programmes must clearly identify sponsors, and that sponsors must not influence the content of the programme in such a way as to impair the broadcaster's editorial independence.

A Home Office spokesman said he was confident Ofcom's rules on editorial independence and sponsorship transparency had been followed in relation to the documentary, adding that the Home Office logo had appeared at the end of the programme.

The first series of Beat: Life on the Street was broadcast on ITV1 last year. It was deemed a success and returned to the screens on Sunday evenings earlier this year. Another documentary, Border Force, which received £400,000 from the Home Office, shows the work of the UK Border Agency and will be broadcast on Sky One this month.

The Home Office said: "Documentaries of this nature play an important role in informing the public, openly and transparently, about the work of the police and UK Border Agency. The Home Office does not influence the content of these programmes after they are commissioned and they adhere to Ofcom's strict guidelines on this kind of programme."

Whittingdale said more should be done to show which programmes were government-funded. "Public information films used to state clearly at the beginning exactly what they were and I think if ministers are going to fund documentaries they must take a similar approach."

ITV insists Beat: Life on the Street was subject to a strict process to ensure it did not break Ofcom's programme-sponsorship rules.

A spokeswoman for Ofcom said officials were examining complaints against the programme before deciding whether to launch a full investigation.